In my experience most of the OpenGL based Star Wars games take a huge performance hit using ReShade with MasterEffect Reborn (Jedi Academy being the worst offender). On the bright side Marty says he's rewriting ME and we can expect a big bump in performance by optimizing his code. It will only get better with time.

The massive framerate hit to 2fps is actually very specific. If you have any lens flare effect (except gaussion anamorphic) activated the framerate dies. Raymarch AO also drops it to 2fps. This happens with these effects in every opengl game I have tried.

Other than lens flares and RMAO, I haven't noticed this problem with any of the other effects in RE.